GREENSBORO, NC -- You know you need to cook meat enough to kill bacteria so you don't get sick.

Don't count on a color change to tell you when meat is properly cooked.

Most of us judge how well it's done by the color of the meat. But restaurants must have a meat thermometer. Chef and GTCC culinary instructor Keith Gardiner explains in this Restaurant Report Card lesson.

"The Health Department wants you to have thermometer that's got a small enough probe that will fit into the meat. The key problems with meat is it is the internal temperature."

Ground beef internal temperature has to hit 155 degrees so you need a small enough probe to go in the center of those ground beef patties. If it doesn't hit 155 degrees, people can get e-coli.

"For poultry, if we don't hit 165 degrees, people can get sick. People can get salmonella. So that's why it's so important hitting those minimal internal temperature for 15 seconds to make sure people are going to be safe."

Gardiner says when in doubt, you're safer to air on the side of over-cooking it for a little than to make somebody sick and risk under cooking it. "Once you establish time and temperature for a certain size piece of meat, it's pretty safe that if you cook all the meat for the same time and the same temperature - you are sure it's going to reach that internal temperature that you need."